Housing cages for holding built-in modules are widely known and are used, for example, for holding drive modules in a drive cage in a computer housing. Because of the wide range of appliances to be accommodated, at least one of the dimensions of the modules to be accommodated is in this case often undefined. For example, 5¼″ drive modules exist of the full standard height and of half the standard height, for accommodation in housing cages. In this case, built-in modules of half the standard height are more frequently used than built-in modules of the full standard height, for which reason the associated housing cages are typically designed with contact surfaces for holding built-in modules of half the standard height.
In order nevertheless to allow built-in modules of the full standard height to be accommodated in a housing cage such as this, it must be possible to remove at least some of the contact surfaces of the housing cage from its interior. This is typically achieved by at least some of the contact surfaces being in the form of an accessory which is screwed into the housing cage later. When modules of the full standard height are installed, contact surfaces such as these which prevent the accommodation of the built-in module are removed from the housing cage again by undoing the screw connection. The belated installation and possible removal of such additional contact surfaces is in this case expensive and time-consuming. The completely assembled housing no longer comprises only the housing cage itself, but also the additionally required contact surfaces.
Alternatively, rails can also be used for holding built-in modules. In this case, the rails are installed in the housing cage only when the built-in module is being fitted. This solution is also relatively complex and requires the rails as a relatively expensive accessory to hold built-in modules.
The effort incurred by the fitting of built-in modules of different standard height during the production of the housing, together with the fitting of built-in modules as well as the costs for the required accessories are not justified by the rarely required function of holding built-in modules of the full standard height.